Normal use of the machine can give full play to its efficiency and maintain a good working condition. What are the problems and solutions of extruder?
1、 Extruder screw wear
1. Cause of wear
The normal wear of the screw and barrel of the screw extruder mainly occurs in the feeding area and the metering area. The main wear reason is caused by the dry friction between the chip particles and the metal surface. When the chip is heated and softened, the wear decreases.
Abnormal wear between the screw and the barrel will occur when the screw is looped and the foreign matter is stuck. Looping refers to that the screw is locked by the condensed material. If the screw extruder lacks a good protective device, the strong driving force may twist the screw, and the jamming will produce an extraordinary huge resistance, resulting in serious damage to the screw surface and serious scratch on the barrel. The scratch on the barrel is difficult to repair. In principle, the barrel is designed to have a longer service life than the screw. The normal wear of the barrel is generally not repaired. The method of repairing the screw thread is often used to restore the radial clearance between the inner hole of the barrel and the outer diameter of the screw.
2. Solution to screw wear
The local damage of screw thread is repaired by surfacing special wear and corrosion resistant alloy. Inert gas shielded welding and plasma argon arc welding are generally used, and metal spraying technology can also be used for repair. First, grind the worn outer circle surface of the screw to a depth of about 1.5mm, and then weld the alloy layer to a sufficient size to ensure sufficient machining allowance. The outer circle of the screw and the side of the screw thread are ground to the original size.
2、 Abnormal noise
1. If it happens in the reducer, it may be caused by bearing damage or poor lubrication, or by gear wear, improper installation and adjustment or poor engagement. It can be solved by changing bearings, improving lubrication, changing gears or adjusting gear meshing conditions.
2. If the noise is a sharp scraping sound, the possibility of scraping between the shaft head and the transmission shaft sleeve due to the deflection of the barrel position shall be considered. It can be solved by adjusting the barrel.
3. If the barrel makes noise, it may be that the screw is bent to sweep the bore or the set temperature is too low, resulting in excessive friction of solid particles. It can be handled by straightening the screw or increasing the set temperature.
3、 Abnormal vibration
If this happens at the reducer, it is caused by the wear of the bearing and gear, and the bearing or gear can be replaced; If it happens at the barrel, it is because hard foreign matters are mixed in the materials. It is necessary to check the cleanness of the materials. If necessary, a strong magnetic device is installed in the hopper to absorb iron filings.
4、 Ring joint plugging material at screw inlet
This fault is mainly caused by the cooling water cut-off or insufficient flow. It is necessary to check the cooling system and adjust the cooling water flow and pressure to the specified requirements. It is also possible that the large recycled material block in the raw material blocks the feed inlet, so it is necessary to clean the feed inlet.
